1. Field of the Invention
The present invention relates to a liquid droplet discharge head and an image forming apparatus, and more particularly, to a structure of a liquid droplet discharge head which discharges liquid droplets from nozzles by applying pressure to liquid by driving discharge energy generating devices (in other words, pressure generating devices), such as piezoelectric elements or heat generating elements, and an inkjet recording apparatus or other image forming apparatus using a liquid droplet discharge head of this kind.
2. Description of the Related Art
In the related art, an inkjet recording apparatus has been proposed in which a pair of electrodes are arranged inside an electrolysis chamber (pressure chamber) filled with an ink containing an electrolytic liquid, the ink being electrolyzed by applying a voltage to the pair of electrode in accordance with information to be recorded, and ink being discharged from a nozzle due to the increase in gas volume caused by the electrolysis (Japanese Patent Application Publication No. 3-104650).
Furthermore, Japanese Patent Application Publication No. 5-286135 discloses an inkjet recording apparatus having a structure in which nozzles are formed on the surface of a rotating drum, and proposes a composition in which ink is discharged from the nozzles by means of the pressure of gas generated by electrolysis of an electrolytic liquid between electrodes, and the centrifugal force of the rotating drum.
Moreover, Japanese Patent Application Publication No. 7-47676 discloses an inkjet recording head and a recording method for same, in which electrodes for electrolysis are arranged inside a common liquid chamber which supplies recording liquid to respective liquid flow channels, provided with a heater forming an energy generating device. By generating gas bubbles inside the common liquid chamber due to electrolysis, variation of the pressure inside the common liquid chamber is suppressed and variation in refilling time between different liquid flow channels is reduced.
Generally, in an inkjet system which uses volatile ink (including water-based inks) or ink that changes properties upon contact with the air, the ink solvent evaporates from the meniscus surface of the nozzles, or the ink changes characteristics, during a normal discharge operation or when the apparatus is at rest (in a non-printing mode), thus leading to variation in properties such as the ink viscosity. Therefore, discharge errors are liable to occur.
Japanese Patent Application Publication Nos. 3-104650, 5-286135 and 7-47676 do not provide any disclosure regarding countermeasures for discharge errors such as there.